Ok, it's been awhile since I've posted (I've been slacking the last 2 weeks.) I have two questions about adjectives. I know how -i and -na adjectives work as far as conjugation... this is more along the lines of how to place them correctly in sentences.

1) The room is beautiful. If I want to translate could I use either of the following, or would only the 2nd one be correct?

a- Heya wa kirei desu.
b- kireina heya desu.

2) I know that suki means to like. So the sentence structure is:

X wa Y ga suki desu.

Watashi wa nihongo ga suki desu. - I like japanese.

But what if i want to say I like to swim. Is there a Oyomu means to swim. Is there a noun form of the word I would use for a contruction like this?

The first explanation about the translation of the room sentence is correct. The second explanation is a little..wrong..

The verb for to swim is 泳ぐ （およぐ）There is a construction for making verbs into nouns (infinitives) to express this type of sentence.
There are also other constructions like adding こと to verbs and other tenses to make them into nouns.

In any case, adding suru to oyogu makes absolutely no sense..
If you wanted to say I like swimming, you could use this formation -
およぐの が 好き です。
The no after the verb is the form to turn it into an infinitive and expresses to swim. This also works in sentences like -
日本語 の 勉強するの は 難しい です。To study(the study of Japanese) is hard.

Going the other route, you can also use koto -
泳ぐ こと が 好き です。 However, koto is a little bit more loosely translated as matter or thing. It would be more appropriate to translate this as I like the activity(matter) of swimming.

To be honest, I have not used a simple sentence like this in a while so hopefully someone like Mukade can explain a little bit moreof the nuances and which is more common.

Actually, "koto" and "no" are pretty much always interchangeable in these instances. The only really big difference is that "koto" is a little (just a little) more formal, whereas "no" is more conversational.

If you think about it, it's easier to say: not only is it one syllable shorter, but it seems to roll off the tounge better than "koto."

Or maybe it's just me.

Either way, you'll hear "no" being used in daily speech a lot more often.